Anterograde Axonal Degeneration in Children with Vision Loss Secondary to NF1 Associated Optic Pathway Glioma (PDF)

The presence and evolution of anterograde axonal degeneration from an acquired optic neuropathy is an important feature to consider when designing treatment and neuroprotection strategies. We studied the association between measures of striate cortex volume and vision loss in children with optic pathway gliomas secondary to Neurofibromatosis type 1 (NF1-OPG).

Tuesday, March 10th from 8:45 - 9:00 am Anterograde Axonal Degeneration in Children with Vision Loss Secondary to NF1 Associated Optic Pathway Glioma Robert Avery1, Ritobrato Datta1, Aditya Rao1, Michael Fisher1, Grant Liu1 1 Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA Introduction: The presence and evolution of anterograde axonal degeneration from an acquired optic neuropathy is an important feature to consider when designing treatment and neuroprotection strategies. We studied the association between measures of striate cortex volume and vision loss in children with optic pathway gliomas secondary to Neurofibromatosis type 1 (NF1-OPG). Methods: Children with and without visual acuity loss from a NF1-OPGs were eligible if they underwent SD-OCT measures of circumpapillary retinal nerve fiber layer (cpRNFL) thickness and brain MRI isotropic T1-weighted sequences on a 3T Siemen's scanner. Using FreeSurfer toolkit, grey and white matter boundaries were segmented after processing and registration to a spherical atlas. Retinotopic visual areas (V1, V2 and V3) were confirmed using a standardized anatomic pediatric template and morphometric measures of volume (mm3) from both hemispheres were averaged. The global cpRNFL thickness from both eyes was averaged and compared to individual retinotopic and whole striate cortex volumes using linear regression. Whole brain volume was also measured. Results: Twenty-seven children (mean age: 7.3 years, range: 4.1 - 11.9) were included. Ten subjects had vision loss (≥ 0.2 logMAR in at least one eye). cpRNFL thickness in the vision loss group was lower than the normal vision group (65 vs. 97 microns respectively, p < 0.01). Average cpRNFL thickness demonstrated a significant positive association with whole striate cortex volume (p < 0.01) even when controlling for whole brain volume (p < 0.02). Individual V1 dorsal/ventral along with V2/V3 dorsal regions demonstrated a significant positive association with average cpRNFL (p < 0.05). Conclusions: Optic neuropathy and vision loss secondary to NF1-OPGs results in anterograde axonal degeneration to the striate cortex. It is conceivable that striate cortex volume loss may decrease the probability of a favorable treatment response as well as the potential success of neuroprotection and visual restoration strategies. References: None. Keywords: Neuroimaging, Genetic disease, Pediatric neuro-ophthalmology, Tumors, Optic neuropathy Financial Disclosures: The authors had no disclosures. Grant Support: NIH EY029687 Contact Information: [e-mail] 304 | North American Neuro-Ophthalmology Society